Abstract <p>A new polyfunctional extractant, 1,3-bis[((hydroxyphenylphosphinyl)acetyl(hexyl)amino)methyl]benzene, has been synthesized. The extraction of REE(III) ions from nitric acid media by solutions of this extractant in organic solvents has been studied. The stoichiometry of the extracted complexes has been determined. The effect of the nature of the organic diluent and the concentration of HNO₃ in the aqueous phase on the efficiency of metal ion extraction into the organic phase has been considered. The extraction capacity of bis(<i>N</i>-hexylcarbamoylmethyl)phenylphosphinic acid based on <i>m</i>-xylylenediamine in relation to REE(III) ions is significantly higher than that of its mono analogue, (<i>N</i>,<i>N</i>-dibutylcarbamoylmethyl)phenylphosphinic acid.</p>